Is central heating common in Luz, SIL? If so, what sort would it be? If not, would people have something else like oil filled radiators or electric fires? I'm mostly interested in relation to the holiday apartments.
In relation to the OC holiday homes, I would think the answer is probably no. Block 6 has a massive propane storage unit outside. Block 4 and block 5 appear to be older, and I can see no suggestion of gas storage.
Block 5 may well have gas hobs, common here, typically powered by a small gas cylinder under the kitchen units. We have a gas hob (and water and CH) powered by a large gas cylinder, which for safeties sake is stored well away from the house.
This may be a legal requirement (big cylinder away from house), but I do not know.
Let me move on to heating, and the potential risk of fire, which is what I think you are actually interested in.
I have not yet heard of any private dwelling being set on fire in the Algarve. We actually have a wooden ceiling, wooden units in the kitchen, and a wooden dining set. After that, it is non flammable concrete, marble, tiles and plaster. If you want to set my house on fire, try a big jerrycan of petrol and a blowtorch. My prediction is no, not going to happen.
There has been one case of a commercial site in Portimão being hit by lightning, and burning most of it down, since we arrived here.
The fires here are mainly in the countryside. The vegetation grows, then dries out, then gets set off into a blaze by some incident.
Was 5A a fire hazard? I think not, but I have not been inside 5A, so I am expressing a personal opinion.